Advances in photoreceptor systems of Echinoderms

The photoreception system is essential for regulating animal spatial navigation and foraging strategies. Echinoderms lack specialized photoreceptive organs and instead utilize diffusely distributed photoreceptors to detect and respond to ambient light stimuli. As key deuterostome invertebrates, they occupy a pivotal phylogenetic position linking protostomes and deuterostome vertebrates. Investigating their photoreception provides critical insights into the evolutionary trajectory of bilaterally symmetrical animals and the molecular regulation of photoresponsive behaviors. This article reviews the morphological and organizational structures of echinoderm photoreception organs, light-sensory behaviors, the identification and characterization of photoreceptors in echinoderms, as well as the mechanisms by which photoreceptors mediated echinoderm light-sensory behaviors. This review also outlines future research priorities and translational applications of echinoderm photoreception studies, aiming to advance both sustainable aquaculture practices (including aquaculture enhancement) for high-value species (e.g., sea urchins, sea cucumbers) and photobehavior-based biocontrol strategies for ecologically disruptive species (e.g., crown-of-thorns starfish).